Switches in the form of load disconnectors for low voltages are known and serve to connect and interrupt an electric current. A pole housing is provided for each current phase, the side walls of the pole housing bearing against one another. Each pole housing contains moving and fixed switching contacts, wherein the moving switching contacts are each located at the free end of a pivotable lever.
In order to open the switch, the contact areas of the switching contacts, which contact areas rest against one another, are separated from one another by a switching shaft, wherein the contact areas each run parallel to one another. The switching shaft runs transverse to the lever and to the side walls. Connection lugs to which connection cables can be connected are located at both ends of the switching shaft. Quenching plates which are arranged in the region of the switching contacts ensure that an arc which is produced when the switching contacts are separated is quenched.
The switching contacts are often in the form of blade contacts, one of which is stationary and the other of which moves.
In this case, upstream elements which are composed of a non-conductive material are provided, the elements causing spreading, so that the stationary or moving switching blade can enter during the connection process without a great deal of resistance. During connection, spreading initially takes place due to the application of force, and the moving or stationary contact blade is then inserted.
One disadvantage is that the connection speed is reduced by the spreading process.